Storage electrode of a semiconductor memory device and method for fabricating the same

A method for fabricating a storage electrode of a semiconductor memory device, the method comprising:

• i) preparing a wafer having a first insulating layer formed with a buried contact plug;
• ii) forming an etching stop layer on the first insulating layer formed with the buried contact plug;
• iii) forming a second insulating layer on the etching stop layer;
• iv) forming a third insulating layer on the second insulating layer, the third insulating layer having an etching rate slower than an etching rate of the second insulating layer when an isotropic etching is carried out;
• v) forming a photoresist pattern for defining a capacitor forming area on the third insulating layer;
• vi) forming an opening by anisotropically and sequentially etching the third insulating layer, the second insulating layer and the etching stop layer by using the photoresist pattern as an etching mask until an upper surface of the buried contact plug is exposed;
• vii) removing the photoresist pattern;
• viii) cleaning a resulting structure such that the second insulating layer exposed through the opening is isotropically etched;
• ix) depositing polysilicon along a profile of the second and third insulating layers to a uniform thickness;
• x) removing the polysilicon deposited on an upper surface of the third insulating layer;
• and
• xi) removing remaining third and second insulating layers.